Electrically propelled household vacuum cleaner



C. A. DOSTAL ETAL Aug. 30f1960 ELECTRICALLY FROPELLED noussnow VACUUM CLEANER Filed July 22, 1955 6 Sheets-Sheet-l FIG. I

FIG. 2

CLARA A. DOST AL INVENTORS i A 'IOBN V Aug. 30, 1960 c, DOSTAL ETAL 2,950,772

ELECTRICALLY PROPELLED HOUSEHOLD VACUUM CLEANER Filed July 22, 1955 6 Sheets-Sheet 2 FIG. 6

CLARA A. 005741. INVENTOPS K A T TOR/VEV Aug. 30,1960 c. A. DOSTAL T 2,950,772

ELEC'I'RICALLY FROPELLED HOUSEHOLD VACUUM CLEANER Filed July 22, 1955 6 Sheets-Sheet 3 CLAI M '4. DOSTAL INVENTQRS K DOSTAL By r i C. A. DOSTAL ET AL Aug. 30, 1960 ELEC'IYRICALLY FROPELLED HOUSEHOLD VACUUM CLEANER 6 Sheets-Sheet 4 Filed July 22, 1955 ATZ'ORNEV FRANK 005 T4 L TOPS CLARA 4. uosmL Aug. 30,1960

c, A. DOSTAL EI'AL ELECTRICALLY FROPELLED uoussaow VACUUM CLEANER Filed July 22, 1955 6 Sheets-Sheet 5 & n a Q m? Q 3 Q 3 Q Q .2 8 .2 R a m Q a u 3 G v n S u QN GD 7 Q GP Q Q m DD. III Q KN w. 9.1 2 Q .3

.Q Q Q n k\ U? c. A. DO-STAL AL 2,950,772 v I Aug. 30, 1960 ELECTRICALLY FROPELLED HOUSEHOLD VACUUM CLEANER Filed July 22, 1955.

6 Sheets-Sheet 6 I CLARA A. DOSTAL 'WENTORS FRA DOST/4L United States Patent 2,950,772 Patented A g- 30, 1960 ELECTRICALLY PROPELLED HOUSEHOLD VACUUM CLEANER Clara A. Dostal and Frank Dostal, both of 29 Welwyn Place, Great Neck, N.Y.

Filed July 22, 1955, Ser. No. 523,677

8 Claims. (Cl. 180-666) The instant invention relates to devices, such as vacuum cleaners, floor polishers, waxers, and the like, particularly of the kinds employed in the average household, which, while in the broad category of labor-saving devices, nevertheless still require appreciable physical effort on the part of the user in propelling them from place to place. The effort so required is frequently enough to prevent the use of such devices by the physically handicapped, semi-invalids and convalescents.

It is an object of the invention to reduce to a minimum the physical, generally manual, effort required to operate various devices of the type which roll on, or travel over, the surfaces on which they act, for example, vacuum cleaners, carpet cleaners, floor waxers, floor polishers, scrubbers, scrapers, sanders, lawn mowers, etc., by making the devices self-propellent by a separate motor but more generally by the electric, or other, motor already incorporated in the device for actuating the work performing element or elements thereof.

Still another object of the invention is to provide household devices of such types which are propellable in the forward and in the backward direction selectively under the control of the user.

Still another object of the invention is to provide de- Vices of the types above mentioned with a switching means to initiate and terminate the power propulsion.

Still another object is to provide devices, for example, vacuum cleaners, for propelling the devices in both the forward and backward directions at the same speed, or with one of such speeds, usually the forward speed, greater than the other.

Still a further object of the invention is to provide vacuum cleaner devices with driving means supplying substantial assistance in making turns.

Another object is to provide increased traction between the rotatable elements of the drive of devices.

Still a further object of the invention is to provide self-aligning action for the driven roller shaft of such devices.

Still a further object of the invention is to provide such a device in which the propelling drive assumes a neutral position when not in operation.

Still a further object is to reduce the amount of time spent even by normal persons in performing the tasks for which the device, for example, a vacuum cleaner or a floor water and polisher, is designed by incorporating in the device the power drive unit of our invention.

Another object is to provide greater cleaning efiiciency as the brush of vacuum cleaners, for example, can be designed so as to provide greater brushing action.

We accomplish the foregoing, and other, objects of the invention by providing at least one set of floor engaging rollers which is power driven by a system of driving rollers including at least one elastic belt and pulley between such set of rollers and a driving motor mounted on the device, or by any other system transmitting rotary motion, such as sprockets, chains, gearing, etc., driven by such motor. Where the motor is an electric motor, it is energized by providing a normally open switch in the handle of the device at the region Where it is usually held, which switch, on grasping the handle about the switch, is closed to connect the line supply to the motor. With the motor energized, when the handle is pulled, the power transmission is so connected to the set of power driven floor engaging rollers that the device is propelled rearwardly, whereas when pushing on the handle, it is so connected thereto as to propel the device forwardly. The means for shifting the direction of power transmission includes a transversely aligned pair of levers to one end region of which the lower end of the device handle is pivotally connected, the pair of levers supporting one shaft of the power driving unit. This lever supported shaft, on which generally the power driven floor engaging rollers are mounted, may be displaced a limited amount from the true transverse direction of the device to enable making power turns by either making the levers of thin material so that they are flexible in torsion about their lengths or by mounting the shaft in flexible inserts in the levers. The main portion of the weight of the device is carried by these levers so that the rotatable elements of the drive which are longitudinally movable in the device tend to assume a neutral position in the unoperated position, since in the operating positions of the levers the other portions of the device are raised relative to the power driven floor engaging rollers.

Our instant invention will more readily be understood from the following detailed description of several illustrative embodiments thereof, in the form of power drives for vacuum cleaners of the upright type, whenv read in conjunction with the appended drawing in which:

Figure 1 is a somewhat simplified elevational side view of a vacuum cleaner incorporating a first illustrative embodiment of the self-propellent driving unit of our invention, in which the parts of the vacuum cleaner not essential to the understanding thereof have been omitted;

Figure 2 is atop view of the driving unit of Figure 1;

Figures 3 and 4 are the elevational side View and top View, respectively, of a modification of the first illustrative embodiment of our driving unit in which the brush shaft is movable longitudinally relative to a fixed floor roller shaft;

Figures 5 and 6 are views, respectively, of a second illustrative embodiment of our power driving unit in which the brush shaft is longitudinally fixed and the floor engaging roller shaft is longitudinally movable;

Figures 7 and 8 are views, respectively, of a third illustrative embodiment thereof in which an auxiliary drive shaft is driven directly by the motor independently of the brush shaft;

Figures 9 and 10 are views of a modification of the third illustrative embodiment in which the floor roller shaft is slidable between two auxiliary shafts;

Figures 11 and 12 are views of a fourth illustrative embodirnent thereof in which the floor engaging power driven rollers house both the forward and rearward driving rollers;

Figures 13 and 14 are views of a fifth illustrative embodiment thereof in which the power driven floor en gaging rollers house one'set of the directional driving rollers, the other set of directional driving rollers being external to such fioor engaging rollers;

Figures 15 and 16 are views of a sixth illustrative embodiment in which the driving rollers are aligned on a pair of levers rotatably supporting the brush roller, the levers being pivotable to engage one or the other set of the directional drive rollers with the floor engaging, power driven, rollers;

Figures 17 and 18 are views of a seventh illustrative embodiment thereof in'which'the directional drive rollers arelongitudinally aligned on brackets tiltable-bythedevice handle to have one set :only of the directional drive rollers engage the power driven floor engaging rollers at any-time;

' Figures;l9- and 20 are views of-' a modification of the seventh illustrative embodiment in which each set of the directional drive rollers are independently driven direct:

the motor 2', by way of adrive shaft 3, drives the brush 4in the mouth of the suction tube of the cleaner, as also at least, one'fantin such suction tube which opens, in well known manner, into a dustcollector orhag; The" fan on rotation creates suction at'the mouth of the tube thereby drawing dustladen airxat such mouth into the tubeand" propelling itrto the dust collector or bag,- in welLknown'manner. Since these latter elements are all well knownin the art, only those essential to the dis-y closure and" understanding of the instant invention are:

shown and referenced. The rear portion of the housing l is. provided with aipair of transversely alignedurollersts, 5, so supported therefrom that with the brush and these; rollers on the floor, the drive shaft 3 is in a predetere mined position, for example, horizontal. V e It is to be understood that the parts so far'enumerated may beofany prior known type, and also that a primed r'eference character means that a like element is transversely opposite the non-primed element in theparticular.

embodiment. Like reference characters in'the'variousfig- 'uresofflthe drawing designate like elements? in the respective embodiments. V For simplicity of the showing in the drawing, all the .top views with the exception of that of Figure 2,, show'only that-half of the devicecontaining thenon=primed element of apair;

V Ihe self-'propelled' unit of our first embodiment' has t a" pair offrame members 6, 6' supported withinthe housing 1, each frame member being spaced from the lateral wallssthereofand extending longitudinally therein. The

brush 4 is fast on the brush. shaft 7iwhich is rotatably supported 1 at its end regions in' the" forward portionsof theframe members 5, 6', the brush side; of the illustrativeembodiments being designated the forward endiof the devicesdescrihed and illustrated in thisapplicationh The brush'is driven by way of the pulley 8' integral withthe z,9rso,772 i .7

. 4 7 17, 17' in such levers. We prefer, more generally, to use plain bearings for journalling the shaft in the levers and to make the latter flexible in torsion of their'length by making them of relatively thin metal or other material and pivoting them through their thickness. Rotatably mounted on the respective ends of the shaft, and spaced from both the frame members 6, 6' and the lateral walls of the housing 1, the floor rollers'18, 18- arecup-shaped with their open ends facing-inwardly, that is, toward'each other. Coaxial with and situated within the interior of the floor. rollers 18-, 18 the rollers19, 19- are integral therewith and of such diameter relative'to that of rollers 18, 18' that when rollers 10,,10-, which are positioned in the interior of rollers 18, 18 engage the interior cylindrical surfaces of rollers 18-, 1 85', they are diserigaged from the rollers 19, 19, and vice versa. 'A pair of matched springs 29, 21 and 211, each anchored at one end in the frame members 6, 6 and connected with its other end to the upper ends of levers 1 1, 11', returnsthe levers 11, 11? to a. neutral position when the handle '14 is released.

An electric. line switch 22 which is spring biased to its openposition, is providedfiin the handle 14 at the upper region thereof. where'it'is normally grasped by the user; of which; switch, the blade, appropriately insulated,

midregion of the shaft ,7, belt 9 and the motorshafti3,

the: brush motion; being in theclockwise, direction as in Figure 1 such that the tufts of thebrush sweep forwardly on the floor. at all times irrespective of the'direction. the device itself is moving. The ends ofithe'brush,

shaft 7 extend transverselyjbeyond the frame members and carry rollers 10, '10 integral therewith, or are themselves formed .assuch rollers, At the rearward regions of' theframe members 6, 6', thelower ends of the levers.

11,. 11 are pivoted at 1 2, 12, with the upper ends. of

such leversipivotallyconnected .to the forked' ends 13; 1.3

extends outwardly from the handle. When the user encircles thehandle-at-that region with his hand, theswitch blade is depressed to close. the circuit, connecting. the line current by way of the usual plug 'to the motor 2;

In operation, the handle having been graspedito close the switch 22 and start. the. motor 2', the brush 4 is rotated; as abovestated, clockwise, and hence also the rollers 10, 10 integral therewith; Pushing the handle 14l'on'gitudinally forward, the levers 11, 11' pivot about 12, 12" to move the shaft-16 in the forward direction un til the cylindrical surfaces of the rollers 19, 19' engage theclockwise rotating rollers 10, 10',,driving'the rollers 19 '19 counterclockwise. Hencethe integral. floor rollers"1'8 ,"'18 are driven counterclockwise and the device is propelled forwardly. Just so long as the slightest of longitudinal pushes is maintainedon the handle, the rolls 7 ers 18,18 will be driven counterclockwise and continue the: propulsion in the' forward direction; However, if a longitudinalpull is exerted on the'handle', the levers pivoting about 12, 12" will move the shaft 16 in the rearward direction v until the interior cylindrical surfaces of the floor rollers 18, 18' areengaged by the clockwise rotating rollers 10, 10', driving-the floor rollers clockwise and" propelling thevacuum cleaner in the rearward direction just so long as the slightest of longitudinal pullsis'niai'nt-ainedon thehandle. V

' If now-it is desired to'negotiate a curve orturn with the vacuumicleaner, the handle 14 is pulled laterally in the direction opposite that offthe desired turn, this being a normal and quite usual maneuver. Thus; as viewed in Figure 2, if the vacuum cleaner is to make "a forward turn' upwardly, the handle 14 at its grasped upper end at the switch 22 would he deflected downwardly'while pushed forwardly. In so doing, the fork 13 would pull the:1ever 11 rearwardly about its pivot 12 causing the interior surface of the roller '18 to engage the roller 10, which, rotating clockwise, drives the roller 18 clockwise and rearwardly, whereas the fork 13f wouldpush the lever'11' forwardly to'causethe roller :19 toengage the and forwardly. It will he notedthat the resilient inserts 17, 17' in thelevers permit of the required deflection of the shaft 1'6 involved in these power turns. t

of the device handle 14 at 15, 15'; The. forked ends 13, r

13' extend through the device ,housinggby way of appropriate apertures. A shaft lfi' is fixedly mounted transverse ly in the. vacuum cleaner in the levers 11, 11' at an inter- 'mediate region thereof above'the frame members 6, 6".

To permit. of slight deflections ,of the shaft 16. from its In, the first illustrative embodiment jus'tjdescribed, the roller 19 being of' a smaller diameter than the floor en-. gaging; power driven; roller 18;: and both hing '5 driven b'y:the roller 10, when in" engagement, with thejoller, 19 in the forward directionyand with the inner cylindri-,

cal surface ofthev roller 18 in the reversedirection, the

normal position substantially perpendicular to .the'levers- 7 11,11, the shaft '16 may be journalled in resilient inserts forward speed. of; theivacunm cleaner of this embodiment exceeds; the backwardspeedthereof.

V In the modification of the first illustrative embodiment shown in Figures 3 and 4, instead of the position of the power driven, floor engaging rollers being controlled, the

brush is so controlled toward and away from the spatially fixed position of the floor rollers. In this modification, the brush shaft 7 extends between the forks 23, 23 at the lower ends of the levers 24, 24' which are pivoted at the intermediate region 12, 12 in the frame members 6, 6'. As before, the rollers 10, are integral vnth the ends of the brushshaft 7, which shaft extends through horizontal, elongated apertures 25, in the frame members, while the upper ends of the levers 24, 24 are pivotally connected to the forked ends 13, 13 of the handle 14. The shaft 16 is supported spatially fixed in the frame members and, also as before, the floor engaging rollers 18, 18, with the forwardly drive rollers 19, 19 internflly thereof, are rotatably supported on the ends of shaft 16. As the handle 14 is pushed forward, the shaft 7 moves rearward in the elongated slots 25, 25 to engage the rollers 10, 19 to the forward rollers 19, 19' to propel the vacuum cleaner forwardly, while when the handle is pulled rearwardl the brush shaft 7 and the rollers 19, iii are moved forward in the elongated horizontal siots 25, 25' and away from the rollers 19, 19 to engage the interior cylindrical surface of the floor rollers 18, 18 to propel the vacuum cleaner rearwardly.

In the second illustrative embodiment, see Figures 5 and 6, the brush shaft is again longitudinally fixed while the floor roller shaft is longitudinally displaceable to cause the floor rollers to engage either the forward drive, or the rearward drive, rollers, each pair of directional drive rollers being on an auxiliary shaft which is belt driven. A first auxiliary shaft 26 is rotatably supported in the forward regions of the frame members 6,5 and a second auxiliary shaft 27 is rotatably supported in the rearward regions thereof. A belt 28 over the pulley 29 rigidly fastened to the transverse midregion of the brush shaft, by way of pulley 30 integrally on shaft 26, rotates the latter shaft in the same direction as that in which the brush rotates. At one end region of the shaft 26, between the frame member 6 and the adjacent wall of the housing 1, for example, the pulley 31 integrally thereon, by way of the crossed belt 32, drives the pulley 33 integrally on the shaft 27 in the opposite direction. The shaft 26 has a pair of integral rollers 34, 34 spaced thereon, while the shaft 27 has a pair of integral rollers 35, 35 spaced thereon, the rollers 34 and 35 being longitudinally aligned with each other, as are rollers 34 and 35. In the transversely aligned slots 36, 36 through the frame members 6, 6, the slidable bearings 37, 37 are respectively supported, the bearings mounting the shaft 16 on the ends of which the independently rotatable and spaced floor rollers 18, 18' are mounted. At intermediate transverse regions 38, 38, the shaft in is rotatably connected to the forked ends 13, 13' of the handle 14. The diameter of the floor rollers 1d, 18' is less than the distance between the most adjacent peripheral regions of the roller pairs 34 and 35, and 34 and 35', that is, on engagement of the cylindrical surface of each floor roller with one roller of the aligned pair of rollers, such surface is disengaged from the other roller of the pair. The length of the slots 36, 36' and of the bearings 37, 37' is such that when the bearings almost abut one end of the respective slots, the floor roller is engaged to one drive roller of the pair and disengaged from the other roller of the pair, while when the bearings almost abut the other end of the slots, the floor roller engages the other drive roller of the pair. In

the embodiment of Figures 5 and 6, just described, we'

5 V drive rollers or by appropriate change in the speed of their respective shafts, or by a combination of both.

In the third illustrative embodiment, shown in Figures 7 and 8, the driving shafts. of the forward and the rearward driving rollers are driven independently of each other by direct belting from the motor to each driving shaft and at the same speed, but the forward driving rollers are made larger in diameter than the rearward drive rollers, so that the forward speed of the vacuum cleaner is greater than its rearward speed. In this embodiment the forward driving rollers 34, 34 are integral at each end of the brush shaft 7, which is belt and pulley driven from the motor as in the previously described embodiments, and similarly the rollers of the rearward driving pair are integral on the rearwardly positioned auxiliary shaft 27 driven by its integral pulley 39 through the belt 44 from the motor shaft 3 in the direction opposite to that in which the brush shaft 7 is driven, but at the same speed since brush shaft pulley 8 and auxiliary shaft pulley 39 have equal diameters. In this embodiment also, the floor rollers 18, 18' turn independently of shaft 16 of which the ends are supported in the levers 11, 11', the latter being pivoted at their lower ends on pins 12, 12 in the frame members 6, 6', the pins 12, 12 being located about midway between shafts 7 and 2'7. It will be noted that the spacing between the rollers 34, 34' on the brush shaft 7 and the rollers 35, '35 on the auxiliary shaft 27 is such that with the levers 11, 11 pushed forwardly to cause the floor rollers 18, 18 to engage the forward drive rollers, there is complete disengagement between the floor rollers and the rearward drive rollers, whereas when the levers are pulled rearwardly to cause the floor rollers to engage the rearward drive rollers, there is complete disengagement between the floor rollers and the forward drive rollers. To maintain more effective contact between the engaging rotating surfaces of the rollers, a pair of magnets 41, 42 and 41, 42 are supported on the frame members in the path of movement of the lever arms 11, 11 to act on the levers in their forward pushed and rearward pulled positions by attracting them and tending to hold the levers thereagainst in the one position by magnets 41, 41', in the other by magnets 42-, 42. While the shaft 16 might be provided with self-aligning bearings in the levers 11, 11', as in the Figures 1 and 2 embodiment, here the aligning requirement is satisfied with plain bearings for the shaft in the levers, since the latter are made flexible in the torsional direction about their length by making them of relatively thin material, preferably metal, pivoted through their thickness as shown.

it is to be noted that as the shaft 16 is swung from the rearmost position, where floor rollers 18, 18' engage the rearward drive rollers 35, 35, to the most forward position, where the floor rollers engage the forward drive rollers 34, 34', the shaft borne by the levers 11, 11 travels in an are rather than along a chord, resulting-in varying the height of the machine from the floor. The extreme motion longitudinally of the shaft l6'need only be of the order of A3 inch, and hence the vertical component producing the upward movement of the machine as the shaft is swung from its neutral position in either direction will be of the order of about inch, which is of such order as not to affect the operation of the vacuum cleaner. The weight of the machine then acts as a force tending to restore the vertical alignment of shaft 16 and the pivot pins 12, 12 having a moment arm equal to the distance the shaft 15 has been longitudinally displaced relative to the pivots 12, 12. The levers 11, 11 will thus assume this neutral position just as soon as the handle 14 is neither pushed nor pulled.

In a variation of the third illustrative embodiment, shown in Figures 9 and 10, the floor roller shaft is slidable longitudinally, rather than swingable by being mounted in a pair of levers, and the directional drive rollers are of equal diameter. The forward drive rollers material rotatably. supported in the rearward region of theframemembers, I Both auxiliary shafts are belt driven opposite. directions directfrom the. motor, shaft 43. by the belt 9 andthe'pulley. 8,.shaft 44 by .the belt 40 and the. pulley. 35!. The floor roller, shaft 16. is slidable in th elongated apertures 36,, 36 in the. frame members and. attransverse. intermediate regions 38', 3$-,ti1ereof is rotatably connected. to theiforked ends 13, 13 of the device handle 14. A. connecting member 45 has its central portion connection .to the shaft 16,.and has a forwardly; extendingrod. 46 and a rearwardly extending rod 47, each rod having a magnet. 48' and 49, respectively, afitsfree end.. The rearwardly extending rod 47 also has a yoke i} atits free end straddling the shaft 44 at all. times irrespective of the. amount of longitudinal displacementofthe connecting member 45 either forwardly or rearwardly. When theshaft 16 is pushed forward by means of handle 14, connecting member 45-is displaced forwardly. andmagnet, 48.attracts shaft 43, thus tightly engaging the forward drive rollers 34, 34 to floor rollers 18,. 18', while when the connecting member is displaced rearwardlymagnet 49-attractsshaft 44 to tightly engage the rearward drive rollers 35, 35 to thefloor rollers.

In the fourth illustrative. embodiment. of our power driveunitshown in Figures ll and 12, the floorrollers 18,; 18' house both the forward drive rollers and' the rearward drive rollers, the forward drive rollers being rotatable. on an auxiliary. shaft supported in the frame The ends of the auxiliary shaft 26 extend 'through. theframemembers6, 6' so as to position the members.

forward drive rollers34, 34' within the floor rollers 18,

r 18. while. the drive rollers 10, are fixed on the respective ends of the brush shaft 7. To permit the passage of the rollers 10, 10' and 34, 34' into the floor engaging,

power driven rollers, the latter are open on their faces adjacent respectively to the frame members 6, 6L. As in are integrally mounted'on the ends of the brush shaft.

the first embodiment, the brush 'shaft'isrotated from the motor shaft 3 byv way of thebelt 9 and the brush shaft pulley 8. The floor rollers 18, 18' are rotatably supported on.the stub shaftsSl, 51"of which the non-roller ends passthrough the frame members 6, 6' and-are fixedly supported inthe levers 11, 11.'. at a region thereof above the pivot-pins 1 2, 12...tl1ereof-in the frame members. To permit the shifting forwardly and rearwardly of the stub shafts by. the lever arms, the elongated apertures 36, 36 are provided in' the frame members, the. stub shafts passing through the. apertures. The forward drive roller. shaft 26 is fixedin the frame members at a distance from the brush shaft 7 so that atv all times the roller 10 engages the roller 34 and the roller 10' engages the roller 34 to drivetherollers 34, 34 in the opposite direction. The diameters of the drive rollers 34, 34 and 1 0, 10' are such that, coupled with the positioning vertically of the brush shaft 7 and theauxiliary shaft 26 below the stub shafts. 51, 51., whenonepairof the drive rollers 34, .34 engage the. cylindrical interior surface of the floor rollers 18, 18, the other pairof drive rollers 10, 10 are. disengaged fromsuch surface.

In operation, when the handle 14 is pushed forward, the levers 11, 11 force the stub shafts 51, 51 forward towards :the forward .endsof t-heaper'tu-res 36, 36 thus moving the. floor rollers 18, 18' forward to bring the inner. cylindrical surfacesthereof into engagement with the forward rollers 34, 34 and driving the hoof rollers counterclockwise and the vacuum cleaner for: ward. On the other hand; when handle 14 ispulled, the leversmovewtheistub shafts rearward toward the rearwardend's'of the apertures'and move the floor rollers cleaner to, move in therealrward dir .tion. Different forward and reverse. speedscan be obtainedlbyv the use.

of-an auxiliary roller on eitherIthe. shaft 7Jor. shaft 26 in the manner'similar tojthat us'ed'in the sixth embodiment. Power turns, of thedevice are possible to either the right orfleft ofthe direction of 'devicemotion by suitably; deflecting. the handle 14 to the left or right, respectively, in-the same. manner as above described for the first embodiment. Due tothe mechanical advantage of the levers 11,w1 1.,-i ncreased traction between the floor rollers and the. drive rollers is obtained In the fifth illustrativeembodiment, shown in- Figures- 13 and 14, only the rearward drive rollers 35, 35 are disposed within the floor rollers '18, 18' and are belt driven from. the brush shaft 7, onwhi'ch the forward drive rollers 34, 34 are integrally mounted. The brush shaft 7 is belt driven fromihefmotor throughthe pulleys which is relatively. large as compared to the pulley 52' integral onthe brush shaft. 'By way of pulley 52, the backward drive roller. shaft 27' is' driven by thelarge pulley 53 integral on such shaft, andthe belt 54; Even though the forward drive rollers 34, 3.4 are "of the same diameter as thebaclgward drive, rollers 35, 35, there results a higher forward thanbackward speed of the floor rollers "18, 18' because the pulley 53 driven by the.

pulley 52 is Iar'geLthanthelatt'er, making the speedfof the. shaft 27 integral with the rollersv 35,351 sewer.

In the. sixth illustrativefembodiment,'showit.inFigures 15 and 16, the brush shaft 7 is supported by a pair of levers 55, 55 and'the forward drive rollers 34, 34'

The brush. shaft also. carries the integral, intermediate drive rollers 56, 5,6 of whichthe, cylindrical surfaces engage those. of the rearward drive, rollers 35, 35 rotating the latter in the opposite direction. Thepurpose of rollers 56, 56 is to provide means for different forward and reyersespeeds. The stub shafts 57, 57- of the rearward drive rollers. 35,,35';are supported in the levers 55, 55, above the brush shaft 7. Atthe regions of. the levers aligned horizontally with the line of contact.

ef the rollers 56, 56 with the rollers 35, 35', the levers are pivotedon pins 58, 58 to the;frame members 6, 6',

the upper ends of the levers'55, 55' being pivoted tov the forked ends 13, 13 of the device handle. 14. The floor roller shaft. is'fi'xedly supported'in the. frame members 6, Kat such distance that the cylindrical surfaces ofthe floor rollers 1 8,18, rotatable on'shaft 16',

- are engageable by the forward drive rollers 34, 34 when the handle is pushed, and by therrearwar'cl' drive rollers 35, 35 when the handle is. pulled; It will be noted 7 that the pivot pins 58, 58' are so located that on pulling rotate clockwise and move the device rearwardly. In. like manner, the'forward motion of the-device is obtained by pushing the device handle forward-thus causing the drive roller-s35, 35 tojd ifs engage from the floor rollers,

and the drive rollers '34., still'i driven clockwise, to engagelthe floor roller-s and rotatethem counterclockwise to move the device forward. In the event thatequal forward and backwardspeedsw are required, the diameter of rollers '56 and. 34 should bethe same size; in fact, the

two rollerscan be one. 1

In t nt u rativeembcd tneu Sho n i ures l7 and 18, thed rive r ollers are'rotatably supported rearward to engage their. inner cylindrical surfaces with the rearward drive rollers. 1.0,.10? which rotate the floor in tiltable brackets pivoted on the framemembers, so

that only one set ofv drive rollers engages 'fthe floor rollers on pushing or pulling the handle of the device. Thebrackets '59, 59"'are pivoted at about their midregion longitudinally at the pins. 60,j 6.0. to thefratne members 6, 6', a nd,haye the lowerend of links 6 1, 61"

fix ly c nne t the b ack t re pe ti y, t e pp endsof the links la ein'g pivotall} connected totheha idle forks 13, 13. The forward drive rollers 34, 34-, and

the rearward drive rollers 35, 35, are rotatably supported at the respective end regions of the brackets'with their outer cylindrical surfaces in rolling contact with each other at all times. The forward drive rollers are belt driven clockwise from the motor, thus driving the contacting rearward drive roHers counterclockwise. Thus when the device handle 14- is pushed, the forward drive rollers are tilted to engage the floor rollers, driving the device forward; while, when the handle is pulled, the brackets are tilted in the opposite direction to engage the backward drive rollers to the floor rollers and drive the ,device rearward.

In the modification of the seventh embodiment shown in Figures 19 and 20, each set of forward drive and of rearward drive rollers, rotatably supported in tiltable brackets, is belt driven directly from the motor. As before, the brackets 59, 59 are pivoted about substantially their midregions on pins 69, 68' in the frame members 6, 6', and the links 61, 631' integral with and extending substantially perpendicularly upward from the brackets have their upper ends pivotally connected to the forked lower ends of the device handle. The forward drive rollers 34, 34-, integral with auxiliary shaft 26 rotatably mounted in the forward region of the brackets, are driven directly to rotate clockwise from,

the motor shaft 3 by way of belt 9 therefrom to pulley 8 on shaft 26. Similarly, rearward drive rollers 35, 35', fast on auxiliary shaft 27 which is rotatably supported at the rearward re ion of the brackets, are directly driven to rotate counterclockwise from motor shaft 3 by way of belt 40 therefrom to pulley 39 integral on shaft 27. In this modification, the outer surfaces of drive rollers 34, 34 and 35, 35 do not ever engage each other and are so spaced from each other and in rela tion to floor rollers 18, 18' that when the forward drive roller of a longitudinally aligned pair of drive rollers in a bracket engages the floor roller aligned with such pair,

, the rearward drive roller of such pair is disengaged therefrom, and vice versa. As in other embodiments herein described, the forward propelling speed may be made to differ from the rearward speed by appropriately dimensioning the diameters of the drive rollers or by appropriate change in the speed of their respective shafts, or by a combination of both. The operation of the seventh embodiment and its modification, including power turns, is perfectly obvious from the prior described detailed operation of hereinbefore described embodiments.

In a further and eighth embodia ent, shown in Figures 21 and, 22, the floor roller shaft is longitudinally fixed and the directional drive rollers are on slidably movable members actuated by the handle through lever anns interconnecting the slide members and the handle, one set of the drive rollers being disposed within the floor rollers. The floor roller shaft 16 is fixed in the frame members 6, 6' and the floor rollers 18, 18' are rotatably supported on the ends of such shaft extending beyond the frame members. The brush shaft 7 is rotatably supported in the longitudinal slide members 62, 62 and extends through the longitudinal slots 63, 63 in the frame members 6, 6', the ends of the shaft 7 carrying the forward drive rollers 34, 34' longitudinally ali ned with the floor rollers. The brush shaft 7 is belt driven from the motor in the clockwise direction and is movable in the slots 63, 63 an amount sufficient to engage and disengage the drive rollers thereon with, and from, the floor rollers depending on the longitudinal position of the slide members 62, 62'. An auxiliary shaft 27 is also rotatably mounted in the slide members 62, 62 and is driven by belt 30 from pulley 31 on the brush shaft to pulley 32 integral on the shaft 27, the latter extending through the longitudinal slots 64, 64- in the frame members. The ends of the shaft 27 integrally support the rearwmd drive rollers 35, 35' disposed within the cup shaped floor rollers 18, 18' and adapted on longitudinal movement of the slide members to engage, and be disengaged from, the inner cylindrical surface of the floor rollers. The pins 65, 65, integral with the slide members are engaged between the forked ends 23, 23' of the levers 66, 6d pivoted at intermediate points on the frame members and connected pivotally at their upper ends to the forked ends 13, 13' of the handle 14. It will be noted that since the shaft 16 is above the slide members, this shaft does not interfere with the longitudinal movement of the slide members. When the handle is pushed forward, the slide members 62, 62' move longitudinally rearward to cause the forward drive rollers 34, 34' to engage the floor rollers, at the same time disengaging the rearward drive rollers 35, 35' from the interior cylindrical surfaces of the floor rollers. When the handle is pulled rearward, the slide members move longitudinally forward to cause the rearward drive rollers 35, 35 to engage the interior surfaces of the floor rollers, while disengaging the forward drive rollers from the floor rollers. Slide members 62, 62' being of relatively thin material, are flexible in torsion about their lengths and thus permit of power turns by deflecting the device handle 14 sideways in the normal manner from the direction of device movement in the manner hereinbefore described for other embodiments.

The ninth illustrative embodiment of the power drive, shown in Figures 23 and 24, is essentially the structure of the embodiment of Figures 21 and 22 as applied to a power drive unit in which both directional drive rollers are disposed within the floor rollers. In the instant embodiment, the floor rollers 38, ll are rotatable on the stub shafts 51, 51' supported in the frame members 6, 6',

the stub shafts being positioned above the slide members 62, 62'. The forward drive rollers 34, 34' are driven by continued direct rolling contact with the belt driven rearward drive rollers 35, 35, which have the same diameter as rollers 34, 34. This results in the rollers 34, 34' rotating counterclockwise and the rollers 35, 35' rotating clockwise, assuming the brush is turning clockwise. Both of the directional drive rollers engage, and are disengaged from, the interior cylindrical surfaces of the floor rollers in accordance with the longitudinal displacement of the slide members, such that when the handle is pushed forward, the forward drive rollers engage such surfaces while the rearward rollers disengage therefrom, and vice versa on pulling the handle rearward. With these exceptions, the structure and the operation including power turns, of the instant embodiment are the same as those of the eighth embodiment shown in Figures 21 and 22.

It is to be understood that the embodiments in respect of which the electric switch 22 is neither shown nor discussed, do in fact, have such switch in the handle 14, and that in all of the embodiments, with the switch closed, on a forward push of the handle of the device, the device will be power propelled forward; on a rearward pull on the handle, the device will be power pro pelled rearwardly, and on deflection of the handle from the direction of device movement, the power unit will propel the device in a turn depending on the direction of handle deflection. Likewise all embodiments will have supporting floor rollers, such as 5, 5' in Figures 1 and 2, not necessarily power driven, to maintain the device substantially horizontal.

It is obvious that the particular speed at which the device, in which our power drive unit is incorporated, is ropelled forwardly or rearwardly, is a matter of the relative dimensioning of the various rotatable elements participating in the drive. For the belts shown in the several illustrative embodiments, pulleys, gearing, sprockets and chains, etc., may readily be substituted. Holding magnets, of the types shown in Figures 7 and 8 or in Figures 9 and 10, may obviously be used to retain the appropriate rollers in contact on pulling or pushing the device handle in any of the embodiments. a.ll embodiments may also be provided with the equalized springs inthe appended claims:

' o ler -Wid a o me t r l e @mnfis.

shown inFigures 1 and 2 able portioniof the roller assembly'to'tlie neutral, post tion in the absence of a push (515 51111. on theEhandle. Fur; thermore, all the embodimentsdisclosing the drive and floor rollers between the frame members may; have them outside the frame members, that is, between a frame member and the adjacent lateral wall of they device,

while those, shown with such rollers outside the fraine members may have them therebetween In a ll ofthe. embodiments in which such rollers are between the frame,- members or, outside of them,"the fr'ame mmbers may be.

the lateral walls of the device per se. The embo di or ents; which show drive rollers, within the floor engaging, power propelled rollers may be modified to have someor all offthe drive rollers outside ofthe.floorrollersfand vice.

versa. The motor actuating the power driveunit of our invention may be a separate motor" individual to such vdrive, rather than. the. motor already built into the. de-

viceto actuate its other functions. 7 All-embodiments having levers may, in their stead, have slide members sup; pprting a shaft of the drive, while all embodiments not showing levers may have them inplace of the anaemiab ow r Various other changes will suggest themselvesto .the.

skilled, worker. in the art without departing from;v the of the instant invention, for-it is to be expressly notedand understood that, the embodiments shownare disclosed not by way of limitation and that our invention-is as broad as the prior art permits and as defined What we claim is: v 1 .,A,propelling unit for household devices rollable on floorscompfising-at leastcnepair of cup-shape ddejvicesupporting rollers, a drive roller associated with each ,sup-.

. porting roller, a central cylindrical post coaxial and integral-.with the supporting roller and extending inthe same direction axially as the cup wall thereoflthe ask sociated drive roller being positioned within the groove. formed between the cup wall and the cylindrical post surface and normally out of contact with 'both and Ora, diameter selectively to engage'but one of the. cup. wall I. and .theicylindrical post surface at a time, adevicehandle,

the pair .of supporting rollersbeing alignedand spaced from each othersubstantially at right angles tothe handle, 'motor meansion the device for rotating all;the-d1ive to assist in restoring, thernov members, a drive roller. integral with each endlreg i n 15' rollers in aprdtermined direction, and means supporting each drive roller its cooperating supportinglroller for relative longitudinal movement underthe control of.

the handle. for selectively propelling the device forward. on. pushing the handle, rearward on pulling the handle,

7 andjinaturn on deflecting the handle. i the sideof the.

desiredturn while pushing or pulling.

2. A vacuum cleaner comprising :a first shaft, a plurality of cleaner supporting rollers. of-which atleas't one.

pair is rotatable "about the first shaft atuoppositeend regions thereof, each of the 'pair'of 'cleaner'supporting.

" rollers having two inner cylindrical surfaces coacenme 'with the roller and radially spaced-from each other", .a. second shaftfrotatably supported, electrical means for. driving the. second shaft in'o'ne'direction, a drive-roller.

at-each end region of wtheseco nd shaft extending intojthe cleaner supporting'rcller pair between the twocyljndrical surfaces thereof and of a diameter less thanthe. adial spacing between such two inner surfacesfand rneans 'selectively to engage-the drive roller at one end of thesecnd shaft with the inner cylindrical surface of the greater radius while; simultaneously engaging the drive roller at thes other endofthe second shaft warms. inner. cylin- 'drical surface ofthe lesser radiusof the respective cleani er support rollers and to engage both drive rollers simul;

' taneously to the corresponding inner" cylindrical surfaces of the respective. cleaner'support rollers of the :3. Awacur'rm cleaner propelling unit according; to claim 2 .inwhich the means: for selectively engaging the, drive- .i drical surfaces of thesupporting rollers topropellthe 5; supporting roller to rotate that roller in thelcleanerrear' rollersclockwise, and" the .drive rollers. are posiu rectangular franremernber, a lever pivoted at its-llower. P' fiQ s si e bf h m -masher handlehe levers heingconnected at their-respectiveupp endszto the handle, and a yieldable resilient hearing-in ach lever; int r ediate the endsfthereof in which the second :shaftis it ur ama 7 4; A householdvacuum'cleaner propelling unitconi prising afirst shaft transverseto the cleaner, acleaneig supporting oller at each end regionof the first first and second'cylindrical surfaces and formed within each cleaner supporting roller, a pain of:

spaced; frame members extending longitudinally cleaner, a second shaft rotatably supported in thef rame oflh ewad Shaf an srm l nga d it? h h f a Second y i a s a t ri ae onenergization rotating thesecond shaft, apair;of .-spaced,:

levers, a resilient bearing at an intermediate region-of each lever supporting an end region ofthe lever being pivotedin the, frame member-at its .levge er'id" a handle, and a pivotableconnection between the 'uppei; end region of each lever andthe handle whereby h ingl thehandle longitudinall v forward, he. drive H V K v a o llei's entire second shaft are engaged to the firstdriven cleaner in theforward direction,-on pullingflhe handle.

'longitudinallybackward the dri e rollers sreengagee to the s'econd cylindrical surfaces ofthesupporting lers] to .propel the cleaner. in the rearward .directioniarid' on.

. deflecting the handle laterally while pushing','one drive roller of theisecond. shaft is engaged to the first cylindrical surface. of one supporting roller to rotate it in thercleaner, forward propelling directionand. the. other drivel'r'ollerfv is; engaged to the second cylindrical'surface of the other pelledin-aturn... a a

5. .A liousehold vacuum cleaner accordingto clainrqin. which each cleaner supporting roller is"cup ward propelling direction, whereby the er -(n rs with; .thefopen end .facingthe .r'nidregion .of thefiistshaft;

the motorimeans rotates the. second shaft and "its drive.

withinthecleaner .supportingrollers' between and s c from the first and second -cylindrical surfacesltherebfl Ax h ousehold. vacuum-cleaner propellii1g,-unit accordingtoclaini-l in-which each .ofl'a pair'fofltension springsonr opposite sides longitudinally ofeachleve h' one end anchored in the upper end regionfof the lever and its other end. anchored in the frame membertowhich the leverfisp ivoted, whereby thel'e'ver tends to. assume. a neutral position in the absence of a force acting; on the handle; V

.region thereof and being pivoted'at'i'ts lower end'iii framememb'er, a handle, and-a pivotalconnect onfbe= tween the upper end region of eachlever andith handle,

whereby on pushingthe handle longitudinally'ifr'ward" thed'riverollers are engagedto the first'cyl r'ica hsur faces within. the supporting rollers to propel ifli cleaner" in the forward direction, on pullirigthe" handled gi= tudinally backward "the drive rollers areehgagecltothe} second cylindrical surfaces 'withinthe cleaner-supporting rollers to propel the: cleaner inthe'rearwarddii ectioni.

and on deflecting the handle laterally while pushing thereon one driving roller is engaged to the first cylindrical surface within one cooperating supporting roller to rotate the latter roller in the cleaner forward propelling direction while the other drive roller is engaged to the second cylindrical surface of the other supporting roller to rotate that supporting roller in the rearward direction, whereby the cleaner is propelled in a turn.

8. A vacuum cleaner propelling um't according to claim 7 in which each cleaner supporting roller is cup shaped with the open end facing inwardly of the cleaner, the motor means rotates the second shaft clockwise, the drive rollers on the second shaft are positioned within the supporting rollers and spaced-from the first and second cylindrical surfaces thereof, and a pair of tension 15 14 springs on opposite longitudinal sides of each lever, each spring having one end anchored in the upper end region of the lever and its other end anchored in the frame member to which the lever is pivoted.

References Cited in the file of this patent UNITED STATES PATENTS 557,486 Burman Mar. 31, 1896 637,015 ODonnell Nov. 14, 1899 668,914 French Feb. 26, 1901 1,493,220 Murname May 6, 1924 2,604,747 Bash July 29, 1952 FOREIGN PATENTS 46,198

Sweden Dec; 13, 1919 

